Import mathomatic-10.9b from pkgsrc-wip.

Import mathomatic-10.9b from pkgsrc-wip.
Packaged by Bruce J.A. Nourish, and slightly modified by me.

Mathomatic is an automatic algebraic manipulator that is self-testing
and strictly follows the rules of algebra.

Mathomatic is an interpreter that can:
  - Solve, simplify, and compare algebraic equations.
  - Combine simultaneous equations.
  - Perform basic calculus operations.
  - Generate the sensitivity formula for one or more variables in an
    equation.
  - Act like a double precision floating point programmable calculator.
  - Perform complex number and polynomial arithmetic.
  - Compute the Greatest Common Divisor of numbers or polynomials.
  - Generate "C" code from equations.